A conventional semiconductor device is known in which a stress film is formed so as to cover a gate electrode and a source/drain region of a transistor. The conventional semiconductor device is, for example, disclosed in JP-A-2007-150238.
According to such conventional semiconductor device described in JP-A-2007-150238, etc., it is possible to improve a driving force of a transistor by generating a stress in a channel region under a gate electrode by a stress film.
However, when a distance between adjacent gate electrodes is small, it is difficult to form a stress film in uniform thickness between the gate electrodes, and a void may be formed in an interlayer insulating film that is formed in the stress film between the gate electrodes or on the stress film. In such cases, according to the conventional semiconductor device described in JP-A-2007-150238, etc., there is a problem that a sufficient stress is not generated in a channel region due to presence of the void, and it is thereby not possible to effectively improve a driving force of the transistor.